State-of-the-art blades and vanes that are employed in modern, high efficiency power generation combustion turbine engines rely on high quality materials such as single crystal alloys and precise control of the part's internal and external dimensions. Because of the large size of these parts, cost-effective manufacturing is being pursued by several routes.
Land-based gas turbines, such as the advanced turbine system (ATS) which is under development, require cost-effective high performance components fabricated from advanced materials. First and second row turbine blades and vanes include complex internal and external geometries, and should be fabricated from defect-free materials. Although components with such features have been developed for aircraft engines, the larger size of power generation turbine components provides a crucial challenge. To date, casting trials have been unable to produce defect-free large components in any significant yields.
An alternative manufacturing approach would be to cast essentially defect-free smaller subcomponents, and to subsequently join them using a high quality bonding process. Currently, however, the required bonding technology for advanced single crystal-containing superalloys, such as CMSX-4, that are targeted for use in ATS-class engines is not available.